The mold is built on the plug. This is made from many layers of fiberglass.

This is the inside surface of the mold.

Here is a molded section of the rear spar fresh out of the mold. You can see the mold behind it.

Now I re-focus on the mold of the plug. This picture shows the top surface of the left side of the center section. A good hard paint mold is important. It takes the parting wax better than a dull mold. Also notice the opening for the oil cooler vent has been properly shaped.

I hope the real wing looks this good!

The gel coat on the plug this is starting to get repetitive.

The mold has been completed for this section.

Here are both top surface molds for the center section.

I built a frame on the new molds. I removed the plug so I could turn the molds over. In this picture I'm placing the plug back in the top surface molds so that I can make the bottom surface molds. Doing it this way assures a perfect fit.

Now I have to fill in the gap at the bottom of the bend in the wing. I couldn't do it when the wing was top side up.

The gap is filled. Lots of foam and body putty. Notice how rough the air scoop surface is. That's the next job.

Again, a lot of foam, body putty, and lots of sanding, and a nice air scoop is formed.

The scoop is taped off with aluminum tape to facilitate making the mold for the scoop. Resin will not stick to the aluminum tape.

The air scoop mold is done.

Here is the mold.

Here is the first air scoop part out of the mold. At this time I realized that I had to make another air scoop for the other side that was identical, but a mirror image. How do you do that?

I cut the air scoop part into thin strips, turned them around, and glued them to some strips of wood.

I lined the inside with heavy paper.

I filled in with body putty.

Then put the part in place with hot glue and bondo. Of course a lot of sanding was done to get that mold on it.

Here are both air scoop molds.

Now this big hole needs to be shaped for the inside of the air scoop. It will be part of mold for the bottom wing skin, and the outside part of the air scoop will be a removable attachment.

The process begins by filling in with foam.

Fiberglass is placed in the hole.

All of the bondo is in place and sanded.

The plug is primed.

The part is painted. I really like this color. I got the paint free from a local shop. It's called "Majestic Amethyst". Someone else had it mixed and never picked it up. I use dark colors so I can see if there are any waves, bumps, or low spots. Notice the channels for attaching the outer portion of the air scoop.

The mold is made and still on the plug.

Even with the good mold and the wax and mold release, I had trouble removing the mold from the plug. Luckily, the damage seen here was to the plug, not the mold.

Here the new mold part is bolted to the rest of the center section molds. The other bottom center section was made the same way. I don't need to show that.

The center section plug is no longer of any use. So I laid it on the floor

And like all the other plugs before, I destroyed it. I have to do this because I don't have the room for all this stuff.